Daniele Lacamera / PicoTCP Featured

Free (GPLv2) TCP/IP stack developed by TASS Belgium

Dependents:   lpc1768-picotcp-demo ZeroMQ_PicoTCP_Publisher_demo TCPSocket_HelloWorld_PicoTCP Pico_TCP_UDP_Test ... more

PicoTCP. Copyright (c) 2013 TASS Belgium NV.

Released under the GNU General Public License, version 2.

Different licensing models may exist, at the sole discretion of the Copyright holders.

Official homepage: http://www.picotcp.com

Bug tracker: https://github.com/tass-belgium/picotcp/issues

Development steps:

  • initial integration with mbed RTOS
  • generic mbed Ethernet driver
  • high performance NXP LPC1768 specific Ethernet driver
  • Multi-threading support for mbed RTOS
  • Berkeley sockets and integration with the New Socket API
  • Fork of the apps running on top of the New Socket API
  • Scheduling optimizations
  • Debugging/benchmarking/testing

Demo application (measuring TCP sender performance):

Import programlpc1768-picotcp-demo

A PicoTCP demo app testing the ethernet throughput on the lpc1768 mbed board.

Last commit 17 May 2013 by TASS Belgium

Diff: modules/pico_tcp.c

Revision:
40:c8ab0d2bba0b
Parent:
37:bdf736327c71
Child:
45:ca30069e49bb
--- a/modules/pico_tcp.c	Thu Jul 11 10:17:25 2013 +0000
+++ b/modules/pico_tcp.c	Tue Jul 16 06:40:35 2013 +0000
@@ -314,7 +314,7 @@
       tcp_dbg("%s: snd_nxt is now %08x\n", __FUNCTION__, t->snd_nxt);
     }
   } else if (hdr->flags == PICO_TCP_ACK) { /* pure ack */
-    hdr->seq = long_be(t->snd_nxt);
+    //hdr->seq = long_be(t->snd_nxt);   /* XXX disabled this to not to mess with seq nrs of ACKs anymore */
   } else {
     tcp_dbg("%s: non-pure ACK with len=0, fl:%04x\n", __FUNCTION__, hdr->flags);
   }
@@ -620,6 +620,7 @@
     hdr->flags |= PICO_TCP_PSH | PICO_TCP_ACK;
     hdr->ack = long_be(ts->rcv_nxt);
     ts->rcv_ackd = ts->rcv_nxt;
+    ts->keepalive_timer_running = 2;    /* XXX TODO check fix: added 1 to counter to postpone sending keepalive, ACK is in data segments */
   }
 
   f->start = f->transport_hdr + PICO_SIZE_TCPHDR;
@@ -629,9 +630,11 @@
 
   /* TCP: ENQUEUE to PROTO ( Transmit ) */
   cpy = pico_frame_copy(f);
-  if (pico_enqueue(&tcp_out, cpy) > 0) {
-    if (f->payload_len > 0)
+  if ((pico_enqueue(&tcp_out, cpy) > 0)) {
+    if (f->payload_len > 0) {
       ts->in_flight++;
+      ts->snd_nxt += f->payload_len;  /* update next pointer here to prevent sending same segment twice when called twice in same tick */
+    }
     tcp_dbg("DBG> [tcp output] state: %02x --> local port:%d remote port: %d seq: %08x ack: %08x flags: %02x = t_len: %d, hdr: %u payload: %d\n",
       TCPSTATE(&ts->sock) >> 8, short_be(hdr->trans.sport), short_be(hdr->trans.dport), SEQN(f), ACKN(f), hdr->flags, f->transport_len, (hdr->len & 0xf0) >> 2 , f->payload_len );
   } else {
@@ -666,8 +669,8 @@
   t->tcpq_out.max_size = PICO_DEFAULT_SOCKETQ;
   t->tcpq_hold.max_size = 2*PICO_TCP_DEFAULT_MSS;
 
-  /* enable Nagle by default */
-  t->sock.opt_flags &= (~(1 << PICO_SOCKET_OPT_TCPNODELAY));
+  /* disable Nagle by default */
+  t->sock.opt_flags |= (1 << PICO_SOCKET_OPT_TCPNODELAY);
 
 #ifdef PICO_TCP_SUPPORT_SOCKET_STATS
   pico_timer_add(2000, sock_stats, t);
@@ -1035,7 +1038,7 @@
   tcp_add_options(t,f, PICO_TCP_FIN, opt_len);
   hdr->trans.sport = t->sock.local_port;
   hdr->trans.dport = t->sock.remote_port;
-  hdr->seq = long_be(t->snd_nxt);
+  hdr->seq = long_be(t->snd_nxt);   /* XXX TODO check correct ?? --> snd_last? otherwise maybe data after FIN */
 
   f->start = f->transport_hdr + PICO_SIZE_TCPHDR;
   hdr->rwnd = short_be(t->wnd);
@@ -1329,7 +1332,7 @@
     tcp_add_options(t, f, 0, f->transport_len - f->payload_len - PICO_SIZE_TCPHDR);
     hdr->rwnd = short_be(t->wnd);
     hdr->flags |= PICO_TCP_PSH;
-    hdr->ack = long_be(t->rcv_nxt);
+    //hdr->ack = long_be(t->rcv_nxt);  /* XXX TODO check: setting ack field with no ACK flag ?? */
     hdr->crc = 0;
     hdr->crc = short_be(pico_tcp_checksum_ipv4(f));
     /* TCP: ENQUEUE to PROTO ( retransmit )*/
@@ -1895,15 +1898,15 @@
   { PICO_SOCKET_STATE_TCP_UNDEF,        NULL,            NULL,              NULL,              NULL,            NULL,            NULL,            NULL     },
   { PICO_SOCKET_STATE_TCP_CLOSED,       NULL,            NULL,              NULL,              NULL,            NULL,            NULL,            NULL     },
   { PICO_SOCKET_STATE_TCP_LISTEN,       &tcp_syn,        &tcp_nosync_rst,   &tcp_nosync_rst,   &tcp_nosync_rst, &tcp_nosync_rst, &tcp_nosync_rst, NULL     },
-  { PICO_SOCKET_STATE_TCP_SYN_SENT,     &tcp_nosync_rst, &tcp_synack,     &tcp_nosync_rst,   &tcp_nosync_rst, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_rst },
+  { PICO_SOCKET_STATE_TCP_SYN_SENT,     &tcp_nosync_rst, &tcp_synack,       &tcp_nosync_rst,   &tcp_nosync_rst, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_rst },
   { PICO_SOCKET_STATE_TCP_SYN_RECV,     &tcp_nosync_rst, &tcp_nosync_rst,   &tcp_first_ack,    &tcp_nosync_rst, &tcp_nosync_rst, &tcp_nosync_rst, &tcp_rst },
-  { PICO_SOCKET_STATE_TCP_ESTABLISHED,  &tcp_send_rst,   &tcp_send_rst,     &tcp_ack,          &tcp_data_in,    &tcp_closewait,  &tcp_closewait,  &tcp_rst },
-  { PICO_SOCKET_STATE_TCP_CLOSE_WAIT,   &tcp_send_rst,   &tcp_send_rst,     &tcp_ack,          &tcp_send_rst,   &tcp_closewait,  &tcp_closewait,   &tcp_rst },
-  { PICO_SOCKET_STATE_TCP_LAST_ACK,     &tcp_send_rst,   &tcp_send_rst,     &tcp_lastackwait,  &tcp_send_rst,   &tcp_send_rst,   &tcp_send_rst,   &tcp_rst },
-  { PICO_SOCKET_STATE_TCP_FIN_WAIT1,    &tcp_send_rst,   &tcp_send_rst,     &tcp_finwaitack,   &tcp_data_in,    &tcp_rcvfin,     &tcp_finack,     &tcp_rst },
-  { PICO_SOCKET_STATE_TCP_FIN_WAIT2,    &tcp_send_rst,   &tcp_send_rst,     &tcp_ack,          &tcp_data_in,    &tcp_finwaitfin, &tcp_finack,     &tcp_rst },
-  { PICO_SOCKET_STATE_TCP_CLOSING,      &tcp_send_rst,   &tcp_send_rst,     &tcp_closewaitack, &tcp_send_rst,   &tcp_send_rst,   &tcp_send_rst,   &tcp_rst },
-  { PICO_SOCKET_STATE_TCP_TIME_WAIT,    &tcp_send_rst,   &tcp_send_rst,     &tcp_send_rst,     &tcp_send_rst,   &tcp_send_rst,   &tcp_send_rst,   &tcp_rst }
+  { PICO_SOCKET_STATE_TCP_ESTABLISHED,  NULL,            &tcp_ack,          &tcp_ack,          &tcp_data_in,    &tcp_closewait,  &tcp_closewait,  &tcp_rst },
+  { PICO_SOCKET_STATE_TCP_CLOSE_WAIT,   NULL,            &tcp_ack,          &tcp_ack,          &tcp_send_rst,   &tcp_closewait,  &tcp_closewait,   &tcp_rst },
+  { PICO_SOCKET_STATE_TCP_LAST_ACK,     NULL,            &tcp_ack,          &tcp_lastackwait,  &tcp_send_rst,   &tcp_send_rst,   &tcp_send_rst,   &tcp_rst },
+  { PICO_SOCKET_STATE_TCP_FIN_WAIT1,    NULL,            &tcp_ack,          &tcp_finwaitack,   &tcp_data_in,    &tcp_rcvfin,     &tcp_finack,     &tcp_rst },
+  { PICO_SOCKET_STATE_TCP_FIN_WAIT2,    NULL,            &tcp_ack,          &tcp_ack,          &tcp_data_in,    &tcp_finwaitfin, &tcp_finack,     &tcp_rst },
+  { PICO_SOCKET_STATE_TCP_CLOSING,      NULL,            &tcp_ack,          &tcp_closewaitack, &tcp_send_rst,   &tcp_send_rst,   &tcp_send_rst,   &tcp_rst },
+  { PICO_SOCKET_STATE_TCP_TIME_WAIT,    NULL,            &tcp_ack,          &tcp_send_rst,     &tcp_send_rst,   &tcp_send_rst,   &tcp_send_rst,   &tcp_rst }
 };
 
 /*
@@ -2005,7 +2008,8 @@
       if (t->x_mode != PICO_TCP_WINDOW_FULL) {
         tcp_dbg("TCP> RIGHT SIZING (rwnd: %d, frame len: %d\n",t->recv_wnd << t->recv_wnd_scale, f->payload_len);
         tcp_dbg("In window full...\n");
-        t->snd_nxt = SEQN(una);
+        //t->snd_nxt = SEQN(una);   /* XXX prevent out-of-order-packets ! */
+        t->snd_retry = SEQN(una);   /* XXX replace by retry pointer? */
 
         /* Alternative to the line above:  (better performance, but seems to lock anyway with larger buffers)
         if (seq_compare(t->snd_nxt, SEQN(una)) > 0)